Kindleporn: Amazon Stays Mum About Its Adult Book Store (AMZN)

Did you know that Amazon sells erotica for its Kindle e-reader? Neither did we. Perhaps that's because Amazon (AMZN) doesn't go out of its way to publicize it. In fact, Amazon is so bashful about its blue material that it won't even tell you how well it's selling.

Of course, Amazon doesn't release much in the way of sales stats for the Kindle at all. But it will tell you how individual titles sell relative to each other. For instance, scroll halfway down this page and you'll see that something called "The Last Lecture" is the fifth-best selling title in the Kindle's non-fiction section. But when it comes to books like "Five Minute Erotica"?No dice.

Our bigger question: Who's buying e-book porn?

Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.